//===- JSONCompilationDatabase.h --------------------------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

//  The JSONCompilationDatabase finds compilation databases supplied as a file

//  'compile_commands.json'.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H

#define LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H

#include "clang/Basic/LLVM.h"

#include "clang/Tooling/CompilationDatabase.h"

#include "clang/Tooling/FileMatchTrie.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/MemoryBuffer.h"

#include "llvm/Support/SourceMgr.h"

#include "llvm/Support/YAMLParser.h"

#include <memory>

#include <string>

#include <tuple>

#include <utility>

#include <vector>

namespace clang {

namespace tooling {

/// A JSON based compilation database.

///

/// JSON compilation database files must contain a list of JSON objects which

/// provide the command lines in the attributes 'directory', 'command',

/// 'arguments' and 'file':

/// [

///   { "directory": "<working directory of the compile>",

///     "command": "<compile command line>",

///     "file": "<path to source file>"

///   },

///   { "directory": "<working directory of the compile>",

///     "arguments": ["<raw>", "<command>" "<line>" "<parameters>"],

///     "file": "<path to source file>"

///   },

///   ...

/// ]

/// Each object entry defines one compile action. The specified file is

/// considered to be the main source file for the translation unit.

///

/// 'command' is a full command line that will be unescaped.

///

/// 'arguments' is a list of command line arguments that will not be unescaped.

///

/// JSON compilation databases can for example be generated in CMake projects

/// by setting the flag -DCMAKE_EXPORT_COMPILE_COMMANDS.

enum class JSONCommandLineSyntax { Windows, Gnu, AutoDetect };

class JSONCompilationDatabase : public CompilationDatabase {

public:

  /// Loads a JSON compilation database from the specified file.

  ///

  /// Returns NULL and sets ErrorMessage if the database could not be

  /// loaded from the given file.

  static std::unique_ptr<JSONCompilationDatabase>

  loadFromFile(StringRef FilePath, std::string &ErrorMessage,

               JSONCommandLineSyntax Syntax);

  /// Loads a JSON compilation database from a data buffer.

  ///

  /// Returns NULL and sets ErrorMessage if the database could not be loaded.

  static std::unique_ptr<JSONCompilationDatabase>

  loadFromBuffer(StringRef DatabaseString, std::string &ErrorMessage,

                 JSONCommandLineSyntax Syntax);

  /// Returns all compile commands in which the specified file was

  /// compiled.

  ///

  /// FIXME: Currently FilePath must be an absolute path inside the

  /// source directory which does not have symlinks resolved.

  std::vector<CompileCommand>

  getCompileCommands(StringRef FilePath) const override;

  /// Returns the list of all files available in the compilation database.

  ///

  /// These are the 'file' entries of the JSON objects.

  std::vector<std::string> getAllFiles() const override;

  /// Returns all compile commands for all the files in the compilation

  /// database.

  std::vector<CompileCommand> getAllCompileCommands() const override;

private:

  /// Constructs a JSON compilation database on a memory buffer.

  JSONCompilationDatabase(std::unique_ptr<llvm::MemoryBuffer> Database,

                          JSONCommandLineSyntax Syntax)

      : Database(std::move(Database)), Syntax(Syntax),

        YAMLStream(this->Database->getBuffer(), SM) {}

  /// Parses the database file and creates the index.

  ///

  /// Returns whether parsing succeeded. Sets ErrorMessage if parsing

  /// failed.

  bool parse(std::string &ErrorMessage);

  // Tuple (directory, filename, commandline, output) where 'commandline'

  // points to the corresponding scalar nodes in the YAML stream.

  // If the command line contains a single argument, it is a shell-escaped

  // command line.

  // Otherwise, each entry in the command line vector is a literal

  // argument to the compiler.

  // The output field may be a nullptr.

  using CompileCommandRef =

      std::tuple<llvm::yaml::ScalarNode *, llvm::yaml::ScalarNode *,

                 std::vector<llvm::yaml::ScalarNode *>,

                 llvm::yaml::ScalarNode *>;

  /// Converts the given array of CompileCommandRefs to CompileCommands.

  void getCommands(ArrayRef<CompileCommandRef> CommandsRef,

                   std::vector<CompileCommand> &Commands) const;

  // Maps file paths to the compile command lines for that file.

  llvm::StringMap<std::vector<CompileCommandRef>> IndexByFile;

  /// All the compile commands in the order that they were provided in the

  /// JSON stream.

  std::vector<CompileCommandRef> AllCommands;

  FileMatchTrie MatchTrie;

  std::unique_ptr<llvm::MemoryBuffer> Database;

  JSONCommandLineSyntax Syntax;

  llvm::SourceMgr SM;

  llvm::yaml::Stream YAMLStream;

};

} // namespace tooling

} // namespace clang

#endif // LLVM_CLANG_TOOLING_JSONCOMPILATIONDATABASE_H